Dietary fiber encourages healthy bacteria

Having a diet rich in fiber is well known for encouraging laxation. New research suggests that having a fiber-rich diet has wider health benefits by encouraging so-called ‘healthy’ bacteria.

A study conducted at the University of Illinois has indicated that regular intake of dietary fiber encourages a shift in the gut toward more beneficial bacteria. The types of ‘healthy’ bacteria encouraged by a change in the diet helps with digestion and can lower susceptibility to conditions like Type 2 diabetes and bowel disease.

The study, as a research brief from the University explains, was undertaken by examining 20 healthy men, who consumed the average fiber intake for the US population, which is 14 grams per day. The men were divided into different groups. One group were given snack bars containing additional fiber (polydextrose,) to supplement their diet; another group were given snack bars containing a different source of fiber: soluble corn fiber. The remainder of the group were given placebo snack bars which did not contain any fiber.

Science Codex notes that, after around 21 days of eating the snack bars, fecal samples were collected from the participants. The researchers analyzed the samples and used the microbial DNA they obtained to identify which bacteria were present. The analysis showed that both types of fiber affected the abundance of healthy bacteria present, whereas the group which had the snack bars without fiber did not show this abundance.

The implications from the study are that scientists could look to modify imbalances in relation to the gut bacteria to support and improve gastrointestinal health. This could be done through encouraging changes to peoples’ diets by people increasing their fiber intake.

The lead researcher for the project, Kelly Swanson, notes the main problem: that few people in richer nations eat enough fiber to encourage the correct types of bacteria with the 14 grams a day average being around half of what is required to maintain a healthy and balanced gut.

The findings were published in a paper in the Journal of Nutrition. The reference is: